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1.
Int J Parasitol Parasites Wildl ; 15: 51-57, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33981570

ABSTRACT

The American pumpkinseed Lepomis gibbosus, was introduced to Europe more than one hundred years ago. Currently it is a common fish in European freshwaters but relatively few specific parasites infect this fish in this new habitat. In Europe only a single species, Myxobolus dechtiari seems to represent the American myxosporean fauna of centrarchid fishes. M. dechtiari was found in both Portugal and Hungary. This species forms plasmodia with elongated shape inside the cartilaginous rays of gill filaments. In the advanced stage of infection, after disruption of plasmodia, small groups of myxospores remain enclosed in the cartilaginous gill rays causing distortions in the filaments. Myxospores were ellipsoidal in frontal view and lemon-shape in sutural, length 12.5 ± 0.46 (12-13.4) µm, width 10 ± 0.37 (9.6-10.4) µm, and thickness 7.4 ± 0.37 (7-8) µm; the polar capsules were pyriform, equal in size, length 5.6 ± 0.21 (5.3-6) µm, width 3.2 ± 0.16 (3-3.6) µm; Seven to eight polar tube coils were arranged perpendicularly to the capsule length. There was a small, round, 0.4 ± 0.1 (0.3-05) (N = 50) intercapsular appendix in the spores. The small subunit ribosomal DNA (ssrDNA) of M. dechtiari differed from other myxozoans sequenced to date. Phylogenetic analysis of the ssrDNA gene sequence placed this species in a clade including actinospores and Myxobolus species: Raabeia type1, Triactinomyxon sp., and Myxobolus osburni infecting the same host fish. The focus of our study was to prove that the pumpkinseed, a fish originated from North-America introduced one of its myxosporean parasite to Europe. Emphasis was put on to demonstrate the unique feature of this parasite causing infection in the cartilaginous gill rays.

2.
Microb Pathog ; 141: 103977, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31953226

ABSTRACT

Bacillus licheniformis, a pathogenic new strain of bacteria is considered as the main cause of high mortalities and economic losses among the ornamental fish farms of India. The present study aimed to investigate the anti-bacterial and Immunostimulant activity of three selected Indian medicinal plants, Allium sativum, Adhatoda vasica and Centella asiatica for treating Bacillus licheniformis PKBMS16 by subsequent experimental and clinical trials using different organic polar and non-polar solvents. The antimicrobial and Immunostimulant activity of methanolic crude extracts of Adhatoda vasica was fractions and active constituents was further characterized by chromatography and mass spectroscopy studies using FTIR, 1HNMR and 13c NMR to identify as well as to determine the nature of the pure compound which is phytol (C20H40O), a diterpene alcohol with a molecular weight of m/z 297. In order to study the in vivo anti-pathogenic influence of the biologically active compounds, phytol were incorporated to the artificial diets at the concentration of 2, 5 and 8 mg/kg and fed to the1.0 × 105 CFU/ml of Bacillus licheniformis PKBMS16 injected experimentally challenged ornamental goldfish Carassius auratus for twenty days. Phytol treated group significantly (P < 0.01 and P < 0.05) reduced the rate of fish mortality. After the termination of survivability assay the estimation of hemato-biochemical parameters have been performed and revealed the significant recovery of health condition on 20th days post treatment. Therefore, the present study concluded that the low toxicity along with high bioactivity and tolerance by lower vertebrate supports the potential of phytol as a new compound for inducing fish immunity.


Subject(s)
Acanthaceae/chemistry , Anti-Bacterial Agents/pharmacology , Bacillus licheniformis/drug effects , Fish Diseases/microbiology , Phytol/pharmacology , Plant Extracts/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Biomarkers , Fish Diseases/drug therapy , Gas Chromatography-Mass Spectrometry , Immunomodulation/drug effects , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Phytochemicals/chemistry , Phytochemicals/isolation & purification , Phytochemicals/pharmacology , Phytol/chemistry , Phytol/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Spectroscopy, Fourier Transform Infrared , Toxicity Tests, Acute
3.
Microb Pathog ; 127: 368-379, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30557584

ABSTRACT

Microbial studies on Catfish revealed that Klebsiella is the most common pathogen causing prevalence of ulcers, fin erosion, and other lesions. During this study, a new strain of bacteria was isolated from Channa punctatus, and molecular identification by 16srRNA revealed the strain was Klebsiella PKBSG14 (Accession no KJ162158). The strain was also PCR positive for two virulent gene wcaG (Accession no LN606595) and rmpA (Accession no LN606594) responsible for inflammatory reactions and induction of innate immune response in the host cell. To study innate immune response induced by pathogenic infection the phagocytic interactive process between the spleen macrophages and KlebsiellaPKBSG14 was investigated using optical microscopy. FACS of splenic macrophages revealed that the phagocytic interaction leads to the process of macrophage cell cycle progression. A detailed study on the macrophage DNA content by performing DNA fragmentation and comet allowed us to study simultaneously host cell division as a function of phagocytosis and the findings unveiled the fact that Phagocytosis of KlebsiellaPKBSG14 aided in macrophage cell cycle progression but was less likely to complete mitosis. Here we also report the cytotoxic effect linked to the infection with KlebsiellaPKBSG14 by performing Cell viability assay, intracellular production of ROS, and mitochondrial transmembrane potential where it manifested itself in impaired cellular function. So, in summary, we simultaneously discovered a new strain of bacteria ie. Klebsiella PKBSG14 as well as deliberately attempted to study the immunomodulatory effect of isolated new stain on Channa punctatus by performing host-pathogen phagocytic interactive experiments, the cell cycle state of the host cell and pathogen-mediated cytotoxicity along with genotoxicity, and our results evidence a new immunomodulatory effect of KlebsiellaPKBSG14 infection on fish splenic macrophages.


Subject(s)
Fish Diseases/microbiology , Fish Diseases/pathology , Immunity, Innate , Klebsiella Infections/veterinary , Klebsiella/immunology , Virulence Factors/immunology , Animals , Catfishes , Cell Membrane/physiology , Cell Survival , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Klebsiella/classification , Klebsiella/genetics , Klebsiella/isolation & purification , Klebsiella Infections/microbiology , Klebsiella Infections/pathology , Macrophages/immunology , Membrane Potentials , Phagocytosis , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Reactive Oxygen Species/metabolism , Sequence Analysis, DNA , Spleen/immunology , Spleen/microbiology , Virulence Factors/genetics
4.
Acta Trop ; 181: 25-34, 2018 May.
Article in English | MEDLINE | ID: mdl-29407849

ABSTRACT

A new species of myxozoan, Thelohanellus goldi n. sp. is described using morphological and molecular data, parasitizing the fin filaments from 18 of 25 host specimens (72.5%) of Carassius auratus collected from different ornamental fish farms of India. Mature spore of the new species were oval to spherical in frontal view having rounded posterior ends and tapering anterior end measures 8.7-10.26 (9.50) × 4.10-7.89 (5.84) µm. The single large polar capsule, round to oval in shape but slightly pointed at the anterior end measuring 4.91-7.63 (5.60) × 2.3-3.1 (2.96) µm and located just below the anterior end of the spore. Polar filament only at distal end with 5-6 loose coils. The most differentiating feature from closely related species was carried out by morpho-taxonomic affinities with previously described species which are tremendously supported by molecular taxonomy by partial sequencing of the 18S rDNA gene resulted in a total of 2124 bp fragment of newly obtained small subunit ribosomal RNA gene sequence of the new species which Exhibit 93-95% homogeneity with other closely related species available in GenBank. The BLAST search and high genetic diversity of distance matrix of Myxobolus sp. did not properly match with any available sequences in GenBank and make sister clade with Thelohanellus caudatus and Thelohanellus habibpuri in the Thelohanellus clade including most of Thelohanellus spp. The study of evolutionary history enables us to understand the evolution of modern species and supports some uncertain topologies which are being presented regarding the morphometric analysis. The severity of myxozoan infection has been assessed in this article by observing the histopathological changes of fins of the C. auratus along with the diversity, distribution and taxonomic description of the new Thelohanellus species with their new host and locality records.


Subject(s)
Animal Fins/parasitology , DNA, Ribosomal/genetics , Fish Diseases/pathology , Goldfish/parasitology , Myxobolus/genetics , Parasitic Diseases, Animal/pathology , RNA, Ribosomal, 18S/genetics , Animal Fins/pathology , Animals , Myxobolus/classification
5.
J Parasit Dis ; 41(4): 940-946, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29114123

ABSTRACT

During the parasitological survey of ornamental fish in India the authors identified two trichodinid ciliophorans for the first time in India, during the year 2014-16 and also revealed that goldfish, Carassius auratus, was the most susceptible species for trichodinid infection. Two ciliophorans have been isolated and identified on the basis of wet silver nitrate impregnation technique followed by taxonomic description, morphometric variability and comparative data with its closely related species. Considering all the important features including diameter, structure of denticles, rays and ciliatures the authors are of the opinion that the identified species are new to science. Hence, the name Dipartiella indiana n. sp. and Dipartiella carassii n. sp. are being proposed here. Till date, only two species of the genus have been described from the edible fish, but no attention has been paid to ornamental fish. Moreover, The present study confirms the first report of this genus from ornamental fish species and added two more species under the genus Dipartiella (Raabe, 1959) Stein 1961 along with new host, locality and prevalence rates.

6.
J Parasit Dis ; 41(2): 523-526, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28615872

ABSTRACT

The communication, dealing with the prevalence of protozoan parasites of the ornamental fish of West Bengal. During the study more than five hundred fish have been examined from five districts namely, Nadia, Hooghly, Howrah, North 24-pargana and South 24-pargana of West Bengal during pre-monsoon, monsoon and post-monsoon season. The study reveals that the intensity of infection is more in case of ciliate parasites. The highest ectoparasitic infection has been recorded during post-monsoon season, i.e. from November to February, followed by the pre-monsoon period while the lowest infection was recorded during monsoon i.e. from July to October which may lead to the conclusion that environmental factors are responsible for spreading infection.

7.
J Parasit Dis ; 41(1): 97-105, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28316395

ABSTRACT

Three new species of Myxobolus are described from the mucous membrane around gill lamellae of carps of West Bengal. The new species have been named as M. muralidharani sp. n., M. nilimae sp. n. from Labeo rohita, and M. harpreetae sp. n. from Labeo bata respectively. Spores of M. muralidharani sp. n. measured 13.84 ± 0.049 (13-14) × 4.95-6 (5.35) µm, with two elongated equal sized polar capsules. Spores of M. nilimae sp. n. measured 15.9-17.1 (16.65) µm × 6.2-7.5 (6.9) µm, with two equal petal shaped polar capsules, 9.0-11 (10.4) µm × 3-3.5 (3.16) µm. In contrast to aforementioned two new species, M. harpreetae sp. n. had two unequal polar capsules, 8.7-9.2 (9.149) µm × 2.9-4.0 (3.45) µm and 7.6-8.3 (7.94) µm × 2.8-3.3 (2.9) µm in each spore, 11.4-13.8 (13.2) µm × 4.9-7.8 (6.51) µm.

8.
J Parasit Dis ; 41(1): 112-116, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28316397

ABSTRACT

During the course of a biodiversity survey of the endoparasitic aseptate gregarines in the Malda district of West Bengal, India, seminal vesicles of the earthworm, Eutyphoeus kherai, Julka 1978 were found to be infested with a new species, Monocystis julkae sp.nov., of the genus, Monocystis Stein (Arch Anat Phys Med 181-223, 1848). The trophozoite is elongated but slightly constricted posteriorly. A tail like protrusion appears in the posterior end. Anterior end is rather wider than the posterior one. The whole body size of the trophozoite measures 102.2-184.0 (126.7 ± 19.9) µm × 40.9-81.8 (58.2 ± 10.0) µm. Size of the nucleus ranges from 10.2 to 16.3 (11.9 ± 1.9) µm × 8.1-12.2 (8.8 ± 1.2) µm. The gametocysts are ovoidal containing two unequal gametocytes. Diameter of it measures 61.3-98.1 (75.8 ± 8.6) µm. Oocysts are navicular and measures 6.9-10.0 (8.7 ± 0.9) µm × 3.0-4.6 (4.3 ± 0.4) µm.

9.
J Parasit Dis ; 41(1): 155-166, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28316405

ABSTRACT

Myxobolus Bütschli, 1882 (Myxozoa, Myxosporea, Bivalvulida, Myxobolidae) is an important parasitic protozoan of freshwater fishes reported from almost all over the world. The severity of infection may lead to mortality of the host fish. The present paper deals with the description of three new species of Myxobolus Bütschli, 1882, Myxobolus sonarpurensis sp. nov., Myxobolus elongatum sp. nov. and Myxobolus petalum sp. nov. from a freshwater minor carp Labeo bata (Hamilton, 1822) and major carp Labeo rohita (Hamilton, 1822) respectively from West Bengal, India. Spores of Myxobolus sonarpurensis sp. nov. measures 12.16 µm × 6.74 µm, with two elongated unequal sized polar capsules measuring, 8.84 µm × 3.019 µm and 7.71 µm × 3.12 µm. Spores of Myxobolus elongatum sp. nov. are 16.23 µm × 7.9 µm with two equal polar capsules 8.896 µm × 3.468 µm and 6.51 µm × 3.46 µm. In comparison to aforementioned two new species, Myxoboluspetalum sp. nov. have two equal polar capsules, 7.905 µm × 2.975 µm (2.9 µm) in each spore, 12.07 µm × 5.95 µm.

10.
Parasitol Res ; 116(2): 511-520, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27815737

ABSTRACT

Severe infections by the protozoan parasite belonging to the genera Myxozoa are causing serious problems in ornamental fish reared in breeding farms. Histopathological study is being used for diagnosis of the severity of diseases. Myxozoan infections result in large scale histopathological damages in different fish tissues. No information is available regarding the histopathological changes of goldfish due to infection with myxozoans. The present study deals with the histopathological changes of the gill, fin, and skin of goldfish, infected with myxozoan parasites along with an ultrastructural study using scanning electron microscope. Several histological alterations have been observed in goldfish, like tissue damage, epithelial hyperplasia, necrosis, anoxia, localized lymphocytic infiltration, excess mucus, cellular necrosis, and epithelial proliferation. The present study revealed the invasion intensified by the occurrence of morphological lesions in the gill, skin, and fin exposed to Myxosporidia, which may lead to respiratory insufficiency in fish and even cause mass mortality.


Subject(s)
Fish Diseases/parasitology , Goldfish/parasitology , Myxozoa/physiology , Parasitic Diseases, Animal/parasitology , Animal Fins/parasitology , Animal Fins/ultrastructure , Animals , Fish Diseases/pathology , Gills/pathology , Gills/ultrastructure , India , Microscopy, Electron, Scanning , Myxozoa/isolation & purification , Skin/parasitology , Skin/ultrastructure
11.
Zootaxa ; 4184(1): 130-140, 2016 Nov 02.
Article in English | MEDLINE | ID: mdl-27811658

ABSTRACT

Trichodiniasis of fishes cause economic losses in the fish industry through mortality and decrease growth rate. Very few studies of these ectoparasites have been made in India. A comprehensive icthyoparasotological survey in some ornamental fish farms of different parts of India has been done since March 2014-May 2015. During the study these trichodinid parasites have been identified from the gills of Oranda Gold Fish (Carassius auratus auratus L.). They are Trichodinella epizootica, Tripartiella viz. Tripartiella bulbosa, Tripartiella copiosa and Tripartiella obtusa. All these parasites have been recorded for the first time from the gills of Oranda Gold Fish (Carassius auratus auratus L.) in India i.e. The paper deals with the diversity and description of ciliophorans parasites of ornamental fish.


Subject(s)
Ciliophora/classification , Fish Diseases/parasitology , Goldfish/parasitology , Animals , Aquaculture , Ciliophora/isolation & purification , Ciliophora Infections/parasitology , Ciliophora Infections/veterinary , India
12.
J Parasit Dis ; 39(1): 110-2, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25698872

ABSTRACT

A study has been done to find out the prevalence of different kinds of parasites in Cirrhinus mrigala (Hamilton 1822) during 2010-2011. It has been found that the temperature variation affects some parasitic infestation over the fish species. It was found that ciliophoran and crustacean parasites are more prevalent from November to February whereas the myxozoan and monogenean parasites are more prevalent from January to April. Considering temperature variation throughout the year it has been inferred that most of the parasitic infections were found between November and April when the temperature range varies from 19 to 26 °C. So from the study it can be concluded that lower temperature elicits the parasitic growth in fishes while the higher temperature retards the growth.

13.
J Parasit Dis ; 34(1): 40-3, 2010 Apr.
Article in English | MEDLINE | ID: mdl-21526032

ABSTRACT

Investigations on the incidence of septate gregarines in shrimp have immense importance because of severe pathogenicity of the parasite. The septate gregarines infect the midgut of shrimp Peneaus monodon and severe infection disturbs the intestinal tissues. Mostly gregarines of the genus Nematopsis have been identified from cultured peneaid shrimp. It has worldwide in distribution. In India, gregarine parasites have so far been reported from penaeid shrimps of Bombay and Kerala. The species which was isolated from the midgut of shrimp Peneaus monodon collected from Kharibari area of Sunderbans. 9 out of 20 i.e. 45% of the randomly sampled hosts were found to be infected with a species of the genus Nematopsis. Different developmental stages including trophozoites, sporadins, and gametocysts of the Nematopsis sp. infecting the shrimp have been isolated. No correlations have been established between incidence of infection and environmental parameters.

14.
Insect Mol Biol ; 15(2): 147-56, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16640725

ABSTRACT

To investigate structure-function relationships in gamma-glutamyl carboxylases, the enzyme from Drosophila melanogaster was characterized. Four cysteine residues were shown to be important determinants for enzymatic activity. Native Drosophila substrates have not yet been identified, but propeptides of human prothrombin and factor IX are recognized by the Drosophila enzyme. The presence of the propeptide region increased apparent affinity by approximately 200-fold, and mutation of a hydrophobic residue of factor IX propeptide (F-16A) decreased carboxylation by 90%, as in the human enzyme. Substrate recognition appears to be highly conserved between the human and Drosophila gamma-glutamyl carboxylases. Inactivation of Drosophila gamma-glutamyl carboxylase by non-sense mutations or insertional mutagenesis by P-element insertion have no apparent effects on growth and fertility under laboratory conditions.


Subject(s)
Carbon-Carbon Ligases/metabolism , Drosophila/enzymology , Alanine/metabolism , Amino Acid Substitution , Animals , Carbon-Carbon Ligases/chemistry , Carbon-Carbon Ligases/genetics , Cell Line , Cysteine/metabolism , Drosophila/growth & development , Fertility , Humans , Mutagenesis, Site-Directed , Peptides/metabolism , Vitamin K/physiology
15.
Radiat Prot Dosimetry ; 100(1-4): 103-6, 2002.
Article in English | MEDLINE | ID: mdl-12382838

ABSTRACT

Despite extensive investigations carried out in LiF:Mg,Cu,P, the nature of the emission centre is not clearly understood. Results of X ray excited emission in this material at room temperature and at 16 K are presented to obtain more data that can throw light on the emission characteristics of this material. At room temperature only a single emission peak is seen around 390 nm but at 16 K the emission appears to consist of more than one emission band. The emission spectra could be fitted with three bands with peaks at 332, 385 and 447 nm. The X ray excited emission at 16 K after annealing at 573 K for 5 min suppresses the 332 nm emission but enhances 447 nm emission. Moreover, annealing at 573 K greatly reduces the emission intensity, which signifies that the luminescent centres are also destroyed in this process. Temperature-dependent X ray excited fluorescence below room temperature provides evidence of the existence of shallow traps, which give rise to a thermoluminescence peak around 130 K. On the basis of the present investigations it is proposed that the complex nature of the emission may be related to the formation of donor-acceptor pairs in this material. The possible nature of this donor-acceptor complex is discussed.


Subject(s)
Fluorides/radiation effects , Lithium Compounds/radiation effects , Thermoluminescent Dosimetry/methods , Copper/chemistry , Fluorescence , Fluorides/chemistry , Lithium Compounds/chemistry , Magnesium/chemistry , Phosphorus/chemistry , Radiochemistry , Spectrum Analysis , Temperature , Thermoluminescent Dosimetry/statistics & numerical data , X-Rays
16.
J Biol Chem ; 276(11): 7769-74, 2001 Mar 16.
Article in English | MEDLINE | ID: mdl-11110799

ABSTRACT

The vitamin K-dependent gamma-carboxylation of glutamate to gamma-carboxyglutamate was originally well characterized in the mammalian blood clotting cascade. gamma-Carboxyglutamate has also been found in a number of other mammalian proteins and in neuropeptides from the venoms of marine snails belonging to the genus Conus, suggesting wider prevalence of gamma-carboxylation. We demonstrate that an open reading frame from a Drosophila melanogaster cDNA clone encodes a protein with vitamin K-dependent gamma-carboxylase activity. The open reading frame, 670 amino acids in length, is truncated at the C-terminal end compared with mammalian gamma-carboxylase, which is 758 amino acids. The mammalian gene has 14 introns; in Drosophila there are two much shorter introns but in positions precisely homologous to two of the mammalian introns. In addition, a deletion of 6 nucleotides is observed when cDNA and genomic sequences are compared. In situ hybridization to fixed embryos indicated ubiquitous presence of carboxylase mRNA throughout embryogenesis. Northern blot analysis revealed increased mRNA levels in 12-24-h embryos. The continued presence of carboxylase mRNA suggests that it plays an important role during embryogenesis. Although the model substrate FLEEL is carboxylated by the enzyme, a substrate containing the propeptide of a Conus carboxylase substrate, conantokin G, is poorly carboxylated. Its occurrence in vertebrates, molluscan systems (i.e. Conus), and Drosophila and the apparently strong homology between the three systems suggest that this is a highly conserved and widely distributed post-translational modification in biological systems.


Subject(s)
Carbon-Carbon Ligases/genetics , Drosophila/enzymology , Vitamin K/physiology , Amino Acid Sequence , Animals , Blotting, Northern , Carbon-Carbon Ligases/chemistry , Carbon-Carbon Ligases/metabolism , Molecular Sequence Data , RNA, Messenger/analysis , Substrate Specificity
17.
J Digit Imaging ; 11(3 Suppl 1): 174-7, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9735463

ABSTRACT

We report here the results of our x-ray fluorescence, photostimulated luminescence, and time resolved laser spectroscopy studies in KCI:Cu. This material seems to possess some desirable properties for being used as an imaging plate in computed radiography. This is a US government work. There are no restrictions on its use.


Subject(s)
Copper , Potassium Chloride , Radiographic Image Enhancement/methods , Spectrometry, X-Ray Emission , Luminescent Measurements , Phantoms, Imaging
18.
J Biol Chem ; 273(10): 5447-50, 1998 Mar 06.
Article in English | MEDLINE | ID: mdl-9488665

ABSTRACT

Conantokin-G isolated from the marine snail Conus geographus is a 17-amino acid gamma-carboxyglutamate (Gla)-containing peptide that inhibits the N-methyl-D-aspartate receptor. We describe the cloning and sequence of conantokin-G cDNA and the possible role of the propeptide sequence. The cDNA encodes a 100amino acid peptide. The N-terminal 80 amino acids constitute the prepro-sequence, and the mature peptide is derived from the remaining C-terminal residues after proteolysis, C-terminal amidation, and a unique post-translational modification, gamma-carboxylation of glutamate residues to Gla. Mature conantokin-G peptide containing Glu residues (E.Con-G) in place of Gla is a poor substrate for the vitamin K-dependent gamma-glutamyl carboxylase (apparent Km = 3.4 mM). Using peptides corresponding to different segments of the propeptide we investigated a potential role for the propeptide sequences in gamma-carboxylation. Propeptide segment -20 to -1 covalently linked to E.Con-G or the synthetic pentapeptide FLEEL increased their apparent affinities 2 orders of magnitude. These substrates are not efficiently carboxylated by the bovine microsomal gamma-glutamyl carboxylase, suggesting differences in specificities between the Conus and the mammalian enzyme. However, the role of propeptide in enhancing the efficiency of carboxylation is maintained.


Subject(s)
Carbon-Carbon Ligases/metabolism , Conotoxins , Mollusk Venoms/chemistry , Peptides, Cyclic/chemistry , Protein Precursors/chemistry , 1-Carboxyglutamic Acid/biosynthesis , Amino Acid Sequence , Animals , Base Sequence , Cattle , Cloning, Molecular , Excitatory Amino Acid Antagonists/chemistry , Excitatory Amino Acid Antagonists/pharmacology , Glutamic Acid/metabolism , Kinetics , Microsomes/enzymology , Molecular Sequence Data , Mollusk Venoms/toxicity , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Peptides, Cyclic/toxicity , Protein Precursors/physiology , Protein Processing, Post-Translational/physiology , Sequence Analysis, DNA , Snails/enzymology , Substrate Specificity
19.
FEBS Lett ; 407(1): 85-8, 1997 Apr 21.
Article in English | MEDLINE | ID: mdl-9141486

ABSTRACT

Peptides from the venom ducts of cone snails (genus Conus) contain gamma-carboxyglutamate residues. The gamma-glutamyl carboxylase responsible for this post-translational modification is localized in the microsomal fraction, strictly dependent on vitamin K, activated by ammonium sulfate, and is associated with endogenous substrate. The K(m) of the enzyme for vitamin K is comparable to that for the bovine carboxylase. However, a propeptide containing substrate related to the blood coagulation protein factor IX, a highly efficient substrate for the bovine enzyme, was poorly carboxylated by the Conus enzyme, suggesting differences in gamma-carboxylase recognition signal sequences and/or structural requirements at the carboxylation site.


Subject(s)
1-Carboxyglutamic Acid/biosynthesis , Carbon-Carbon Ligases , Ligases/isolation & purification , Mollusk Venoms/metabolism , Protein Processing, Post-Translational , Snails/enzymology , Animals , Dose-Response Relationship, Drug , Ligases/drug effects , Microsomes/enzymology , Species Specificity , Substrate Specificity , Vitamin K/pharmacology
20.
Br J Clin Pract ; 51(2): 125-6, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9158259

ABSTRACT

A 64-year-old female presented with episodes of small bowel obstruction. Ultrasound and barium meal showed a polypoidal lesion in the proximal segment of small bowel. The patient underwent emergency surgery because of signs of impending acute intestinal obstruction. Pathology showed characteristics features of an inflammatory fibroid polyp (IFP) which is an important though rare benign cause of small bowel obstruction. We document clinical and pathological aspects of this case.


Subject(s)
Ileal Diseases/etiology , Ileal Neoplasms/complications , Intussusception/etiology , Polyps/complications , Aged , Female , Humans , Ileal Neoplasms/pathology , Polyps/pathology , Recurrence
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